This invention relates to motorized three-wheel vehicles having a front engine, two driving and steering front wheels, and a single rear wheel.
Canadian and American patents of the turn of the century disclose such motorized three-wheel vehicles. But these vehicles are heavy farm tractors will all-steel wheels, without suspension and with a high center of gravity. They were designed for farm work and they cannot be utilized on roads at high speeds.
More recently, a sort of three-wheel vehicle much better suited for road driving was derived to be used as a sports car. The vehicle has a front engine driving two front wheels which can also be steered to the right or left in order to steer the vehicle on the road. Thus, these two front wheels drive and steer the vehicle, exaclty like the two front wheels of a front-engine and front-drive four-wheel car. Furthermore, this three-wheel vehicle has two side-by-side seats behind the two front wheels, and it only has one rear wheel which is non-driving and non-steerable.
Such a three-wheel vehicle has a higher proportion of its weight on the two front wheels, than a front-engine front-drive four-wheel car, which already has a higher proportion of its weight on the two driving wheels than a standard front-engine rear-drive four-wheel car. This high weight proportion on the front wheels provides for more protection of the occupants in front-end collisions. It also provides more straight ahead stability against side-wind gusts at medium and high speeds. And it provides for excellent traction and steerability in snow, even better than that of front-engine front-drive four-wheel cars.
The problem with such a three-wheel vehicle is that the occupants enclosure must be as wide as for a conventional four-wheel car in order to sit these occupants side by side. And the width of the front wheel track must be even wider than that of such a conventional four-wheel car since the two front wheels of a three-wheel vehicle are the sole means for providing stability against roll-over in curves at high speeds. Thus, this three-wheel vehicle is very wide, which limits its ability to park or circulate in urban traffic and which increases its frontal area, thus increasing the aerodynamic drag and fuel consumption.
One could think of modifying this three-wheel vehicle by using the front and rear seat lay-out of a conventional four-wheel car to reduce the width of the occupants enclosure. The problem with this lay-out is that the driver has to be seated more towards the rear, behind the trasmission which is located in between the two front wheels, and the passenger has to be seated even more towards the rear to provide him with sufficient leg room. Thus, the vehicle-occupants center of gravity is shifted towards the rear wheel which plays no role in providing stability against roll-over. So the track width has to be even wider to provide the necessary stability against roll-over, for road driving. In other words, there is no obvious modification that may be brought to obtain a simple, small, low cost and still safe vehicle.